Electrical window operator and tension limiting device



ELECTRICAL WINDOW IIIIIIIIIIIIIIIIIIIIIIIIIIIIII CE Sept. 14, 1943. E. H. LUNKEN ET AL ELECTRICAL WINDOW OPERATOR AND TENSIOMLIMITING DEVICE ori inal Filed Feb. 15, 19:59

5 Sheets-Sheet 2 a m P 1N VENTOR. gearge G. 34451 (Edmund if. a? "fen ATTORNEY.

Sept. 14, 1943. E, H. LUNKEN ET AL 2,329,280

ELECTRICAL WINDOW OPERATOR AND TENSION LIMITING DEVICE Original Filed Feb. 15, 1939 5 Sheets-Sheet 3 IN VENT OR.

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Sept. 14, 1943.

E. H. LUNKEN ET AL ELECTRICAL WINDOW OPERATOR AND TENSION LIMITING DEVICE Original Filed, Fb. 15, 19:9 5 Sheets-Sheet 4 6 i F") 64. I 516 {I I I J ZOa J21 61 I @15 I, fff; L 604 5 F l G 7 1: 6 610 Eva 6Z1 0 Z 601 76/ [/k 3 l l 09 .1: F IG.6 700 t 611 INVENTOR.

8 orge Q. BY g 619 914.5! mu 11.4 if. flanker:

Sept. 14, 1943.

E. H. LUNKEN ET AL ELECTRICAL WINDOW OPERATOR AND TENSION LIMITING DEVICE Original Filed Feb. 15, 1939 5 Sheets-Sheet 5 FIGJI.

FIG 2 INVENTgR.

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'BY $14127 Gunter! ATTORNEY.

Patented Sept. 14, 1943 I ELECTRICAL WINDOW OPERATOR AND TENSION LIMITING DEVICE Edmund H. Lunken, Hartsdale, and George A.

Just, Scarsdale, N. Y., assignors to Lunken- Just Window Corporation, Scarsdale, N. 'Y., a corporation of New York Original application February 15, 1939, Serial No. 256,430. Divided and this application September 20, 1939, Serial No. 295,766

mm. (01. ass-124) This invention is a true division of our application Serial No. 256,430, filed February 15, 1939,

and relates generally to novel methods and -means for operating closures for buildings, in-

cluding window sashes and doors.

In our above-mentioned application, we have described a novel window construction which, in addition to other elements therein set forth and claimed, also describes a window sash support which need not rely upon counter-weights, spring balances, or other types of balances for its operation, which would require a simple and inexpensive housing, rather than the complicated housings theretofore in use.

One element which contributed to such simplification of the window unit as a whole is the type of operator which itself is simple, inexpensive and, if desired, automatic in operation.

Accordingly, an object of this invention is to provide asliding closure operator which is convenient in use, simple and economical in manufacture, and which will not rely on counterweights or balancing of any kind for its operation. c

A further object is to so arrange said operator that it may readily be used not merely for slidin window sashes, but also for sliding doors, or closures of any kind; and so that it may be used for raising and lowering any object including the end of a door or window hinged at the top; and so that it may be used irrespective of the direction of movement, horizontal, or vertical, of the sliding member.

Another and important object of the present invention is to provide an electrically controlled operator which through a cable will raise or lower the sliding closure to which the cable is attached, said operator having limiting means responsive to variations to a predetermined extent from a predetermined constant in thetension on the cable for bringing the operator automatically to a halt when such predetermined limits are reached.

Still another object is to provide an operator I .which will function automatically between predetermined limits in the opening'or closing of hinged or otherwise movable closures.

Still another object of this invention is to provide an electrically controlled window operator which will raise or lower a sash which need not be counterbalanced.

Many of the mechanical aspects of the present operator of this application are set forth in our application Serial No. 296,118, filed on September 22, 1939.

Other objects and uses of this invention will in part be apparent and in part be pointed out in the follawing description taken in connection with the drawings, in which:

Figure 1 is a view in perspective showing a series of window units, each having one form of our novel operator.

Figure 2 is a schematic view of a system for our novel operator.

Figure 3 illustrates in perspective schematic view a commercial adaptation of our operator.

Figure 4 is a view in perspective of our pre ferred-form of operator. 7

Figure 5 is a view in perspective of the outer covering of the operator of Figure 4.

of Figure 1 showing the application of our operator of Figure 9 to the window units of Figure 1. Figure '7 illustrates a modified application of the tension limiting element of our operator and is a cross-section on line 1-1 of Figure 8. Figure 8 is an end view on line 8-4 of the member of Figure 7.

Figure 9 illustrates a further modified application of the tension limiting element and is a cross-section'on line 9-9 of Figure 10.

Figure 10 is an end view of the element of Figure 9 taken from line Ill-4|! thereof.

Figure 11 is a cross-sectional view on line ll-ll of Figure 1 corresponding to Figure 6, but showing the operator of Figure 4 as applied to the window units oi Figure 1.

Figure 12 is a view in perspective showin a modified mounting of the tension device on the window unit.

1 Referring now to the drawing we have shown in Figure 1 a series of window units corresponding exactly tothe window units shown in Figure dow units, we have also illustrated therein an electrical method for operating each of said units; said electrical method therein disclosed corresponds exactly to the method shown in Figure 2 of the present application which is divided out of our aforementioned prior application.

In each of the instances herein described, the

operator may function properly irrespective of variations in the weight of the sash due to breakage of panes thereof, addition or removal of storm panels, removal of the screen or any spring tension exerted through the screen or any other cause.

Ordinarily in the construction of window units, for instance, various space consuming and expensive means must be provided for counterweighting, counterbalancing, spring balancing or other forms of balances and operators for windows. In our aforementioned app i i We have described window units which require no such space consuming and uneconomical means but which by reason of the operators, mechanical, manual or electrical therein described, may be constructed very simply and inexpensively without weight boxes or balances of any kind.

This has been made possible by the use either of the manual operator specifically described in the aforementioned application, and in the copending application Serial No. 296,118 filed Sept. 22, 1939, and by the electrical operator likewise described in the aforementioned application Serial No. 256,430, and more particularly set forth in the present application.

Referring now to Figure 2, we have diagrammatically illustrated one method by which a the full weight of the window is still borne on the cable 8| so that the idler ill tends to remain in the selected neutral position. When, however, the window sash reaches the bottom of its path, then the weight of the window sash is no longer borne by the cable ll so that the cable furnishes no resistance to the tendency of the spring ill to pull the end ill of the lever arm ill and the idler pulley ill in a-downward direction, and the insulated member ii! is corzo respondingly caused to rise.

When therefore, an electrical motor ill is connected in any suitablemanner todrivethedrum I", then, when the circuit is made from the terminals ii! and iii of the motor through the double-throw, double-pole switch iii, and the power supply iil through the member iii to the spring switch iii mounted by the member ili, the motor rotates in a direction to wind-up the cable 8| on the drum and thus raise the window.

a whenthewindowsashisfullyraisedandincreased tension upon the cable 8| causes the depression of the member ii! in a manner hereinbefore described, the member ill then bears against the switch iii and breaks the circuit wind-up drum I81 may be rotated for raising or at that'pcint which energizes the motor to rotate lowering a sash which is suspended by the cable 8|. The cable 8| may be attached to the bottom or top or any other suitable portion of the sash as hereinafter described; it is led over the pulleys lli past the idler ilil onto the wind-up drum I". The idler ill is rotatably mounted on the lever ill. The lever ill rotates about its fulcrum iii, one end thereof iii being engaged by the spring ill which limits its rotation.

The opposite end of the lever carries an insulated non-electrically conductive member ilI fastened thereto in any suitable manner as, for instance, by the screw iii, permitting adjustment of the member iii. It will thus be noted that any increase in the pull of the cable OI upon the idler ill will cause the end iii of the lever ill to rise against the tension of the spring ill while any decrease in the tension of the cable ll upon the idler ill will permit the spring to pull the end ill of the lever ill in a downward direction.

Such motion will be translated through the fulcrum iii to the opposite end of the lever where the member ii! will be caused to move in a correspondingly opposite direction. Where the wind-updrum "I is caused to rotate in a direction for raising the window, then a certain tension equal approximately to the weight of the window sash will be applied upon the cable ll, thus tending to raise the idler ill. The spring ill is adjusted to resist the rise of the end'ili of the lever when such normal tension is applied upon the idler ill by the cable ll, When, however, the window is raised to the fully closed position, then any further rotation of the wind-up drum I" will place increased tension upon cable II by reasonof the fact that the sash has been brought to a complete stop. Such increased tension will thus cause the cable CI to tend to the drum in that particular direction, thus stopping the rotation of the motor and therefore the rotation of the drum.

When, thereafter, the double-throw, double- 40 pole switch is then turned to engage the oppomte circuit, the polarity of the motor is reversed, the motor rotates, in the opposite direction, connection having been made through the spring switch iil moimted by the member. iii and through the member iii to the motor ill. When the window sash is thereafter by this lowering action of the motorbrcughttoa stop atthe bottomofits path, the decrease in the tension on the cable ll permitsthememberilltoriseinthe manner so hereinbeforcdcscribedtobearagainsttheswitch 2", thus the contact iii and thus breaking the circuit to the motor for that particular direction of rotation, thereby halting the rotation of drum Ill.

It should be noted that the operation may I...

brought to a stop and/or reversed at any point and that it is not to complete the movement in one direction before commencing the motion in the other.

By thi means, the wind-up cable. tape or chain," andtheassociateddrummaythusbe connected in a member to beelectrically operated. Suitable releasable braking mechanism may be applied on the slmft of the motor ill or upon the q shaftofthednnnllioratanyotherdesiredposition, such braking mechanism being, if desired,

l when any circuit is closed'through the doubleoperated by a solenoid in the electrical circuit, said solenoid being actuated to release the brake throw, double-pole switch 22!, or the drum I maybegeareddirectlytothemotorthrough worms or worm gears of sumciently high gear ratio to be self locking.

- The connection between the motor in and the straighten out, thereby raising the idler ill and 7 drum I" may be made by appropriate gearing,

by belt drive, or by any other suitable. means. The electrical motor 203 and the accompanying electrical circuit is shown merely as an illustration of one method of electrically'operating the sash raising and lowering device. Other methods using other types of motor and other types of circuits will be obviou to those skilled in the art. I

A single motor may be used in connection with and to control the sash of a single window unit or the sashes of a plurality of window units; or a single switching mechanism may be used to control a plurality of motors each mounted on and operating an individual window unit; or individual switches and motors may be provided for each window unit; and remote control of the motors and operators may also be provided, as well as automatic trips to close the w ndows during a rain storm and operated by a suitable water-trip or capsule; thermostatic, photo-electric or capacity screen control may likewise be used.

Obviously where the connection between the motor and the drum is a high ratio gear train, then the friction developed in the gear train itself will serve to prevent reverse rotation thereof, and thus serve to brake the drum and hold the window sash in any wholly raised or partially raised position in which it may be left. w

Thus where a worm gear connection is used between the motor and a drum with the high gear ratio being at the motor end so that the drum when driven is driven very slowly, then the friction developed in the worm gears is suflicient to resist a substantial force against the low ratio and of the system with suflicient resistance to overcome the weight of the sash suspended from the cable and thereby to support the window in any wholly or partially raised position and to lock the window.

It will be understood that any type of reversible motor may be used, the motor having the necessary windings and circuit connections which will be clear to those skilled in the art to'be controlled by the switches above mentioned. In special, cases, it may even be possible to use a separate motor forraising the sash and another for unwinding the drum to lower the sash, appropriate connections being again made to the switches. Or the motor may be used merely to wind up the cable and a solenoid brake release utilized for controlling the unwinding of the cable.

In Figurc 4 we have illustrated a modified form using, however; the same circuit connections and switching means. We have found that while the system of Figure 2 is operative andyperforms the functions required of itin the raising and lowering of sliding closures and in the operation of the switches within predetermined limits of tension on the cable II, the use of a single spring 214 makes it relatively difllcult to adjust this member and it becomes desirable to have separate adjustable compression springs which will control the movement of the lever; such adjustability also avoiding the necessity for a'snubbing arrangement to resist hunting" of the lever.

Accordingly, in the structure of Figure 4 which represents a diagrammatic illustration of the preferred form which we have found most cilicacious in use, the lever 3 is pivoted on the bearin 3i2. The motion of the lever 3 about its bearing is limited by the springs M411 and 3 I422, the operation and function of which will be hereinafter described. The bearing 3|2 preferably i mounted on'back plate 3l5. The limiting springs 314a and 3l4b likewise are limited in final effect by the abutments 3l6a and 3161) which also are mounted on the back plate 315.

Switches 3" and 3l8 are switches of a type which are normally closed and are mounted on the insulated blocks 3H and 320 which may also be mounted on the back plate 3 l 5 in any suitable manner.

The switch 3" comprises preferably a pair of of the free unpivoted end of the lever will cause it to strike against the extensions 325 thereby raising the spring plate 324 causing the contact points 32I and 322 to separate and thus breaking a the circuit therebetween. In the same manner contacts 326 and 321 are respectively mounted on spring plate 328 having the insulated extension 323 and plate 330 which are themselves attached to either side of the insulated block 320. Y

A dropping of the free unpivoted end of the lever 3 will cause the same to press against the 0 extension 323 of the spring blade 328 thus causing a separation of the contacts 326 and 321 and an opening or disconnection of the circuit in which those contacts are placed.

In order to obtain exact adjustment compression, spring 3I4a is provided between the unpivoted end of the lever and the abutment 3|6a and tends to resist the raising of the lever. As will be seen, the spring is captured on the extending pin 33! of the lever and the threaded .pin 332 of the abutment 3llia. The nut 333 may be adjusted on the threaded pin 332 in order to adjust the load under which the spring will permit a suflicient rising of the unpivoted end of the lever to cause a breaking of the circuit between the contacts 32l and 322.

The same or similar arrangement may be fol lowed for the spring 3141: which may be readily adjusted to resist a dropping of the end of the unpivoted end of the lever to break the circuit between the contacts 326 and 321. In this case, adjustable screw 35| is mounted in member 3l3b and has an enlarged end 352 which captures spring 3l4b between itself and the body of the lever. Where the weight of the sash or tension thereon varies, rotation of screws 333 and/or 35l will reset the lever in balancing position.

Obviously the only force which will cause a rise of the unpivoted end of the lever will be tension upon cable 3|. Accordingly, spring 3l4a will necessarily be required to resist greater compression than spring 3|4b. If this operator is used, therefore, in connection with a window sash support by cable 8|, then the cable 8| passing over the pulley 343 which changes the direction thereof and passes over the idler 3 which is freely mounted upon the pin 342 carried by the lever 3| l. Thence the cable passes to the wind-up drum I33 which preferably througha suitable worm gear system 343 is driven by the motor 344. The spring 3l4a is adjusted so thatit will not permit any substantial rise of the unpivoted end of thelever 3| I under the influence of the normal weight of the sash upon the cable 3|, it being noted, however, that any pull on the cable ll will tend to raise the idler pulley 34! and normally tend to cause the unpivoted end of the lever 3 to rise. Accordingly, when the wind-up drum I" is rotated in a direction to cause the winding up of the cable II and the corresponding rise of the sash, then the spring Illa will tend to preventthe raising of the unpivoted end of the lever. If, however, the switch to the motor driving the wind-up drum is left on after the sash has been raised to its greatest height or stopped, then continued functioning of the motor will cause a continuous rotation of the wind-up drum 483, thus exerting a greater tension on the 'cable 8! than would be normally exerted by the window sash itself. The compression spring 3 Ila is so adjusted that under the influence of such super-normal tension upon the cable and therefore on the idler pulley I it will permit a raising of the unpivoted end of the lever II I. The raising of this unpivoted end of the lever ill will cause the lever to strike against the extension 325 of the spring blade 222 which carries the contact HI and thusbreak the circuit through said contacts and stop the operation of the motor in that direction but leaving the cir cuit closed for operation in the opposite or opening direction.

If the sash should stick or be caught at any point in its travel, there will be no overload on the circuit and no fuse will blow. The appropriate switch in the operator will simply be opened.

The worm gear connection 342 between the motor 3 and the drum III by its own internal friction furnishes a suitable brake to prevent the dropping of the window sash and automatically looks it at any point. It should be noted that the contacts 328-321 closing the circuit to the reverse position of the motor thusremain closed during the raising operation so that when the switch 350 is thrown to make a circuit through the contacts 326-321, the motor may operate to turn the drum I83 in an unwinding direction, thus permitting the dropping of the sash connected to the cable ll. As soon as the dropping operation begins, the lever arm 3 returns to its balancing condition predetermined by the weight of the sash which remains upon the cable 8| and the contacts 321 and 322 are immediately closed.

However, the circuit in the lowering position of the sash is made through the contacts 32' and 321. The lever arm is prevented from dropping down to disengage these contacts principally by reason of the fact that the weight of the sash upon the cable ll tends to counterbalance the effect of the spring illa upon the end of the lever arm 3, keeping it in a neutral position.

Spring mo serves to provide a finer adjustment of a balancing i tending to limit position.

When the window sash reaches its lowest point or stops because of sticking or other cause and can descend no further, then continued rotation of the motor will cause a slackening of the cable ll; the tension on the cable ll thus decreases, no resistance is then offered to the influence of the compression spring 3H0 by the weight of the window sash and the said spring may then drive the unpivoted end of the lever down so that it strikes the extension 32! of the spring blade 32' thus separating the contacts 22 and 321 and breaking the circuit to the 'motor once more and causing the motor to cease its operation in that direction.

It will be noted, however, that the contacts I,

hunting 222 are now in closed position so that a throwing of the switch so that the motor is reversed and the current flows through those contacts will cause a raising of" the window sash.

Spring "4b is provided principally to obtain greater delicacy of adjustment. Obviously, it need not be as strong as spring Illa and obviously should not overcome in any respect the tendency of spring Slla to depress the unpivoted end of the lever arm when the weight of the sash is removed from the cable II by the fact that the sash has dropped to its lowest limit.

Instead therefore of having a single spring which is subject to extension and compression, only a compression spring is necessary and for delicacy of adjustment an additional compression spring preferably of lesser tension may be provided acting opposite to said first spring in order to prevent any hunting and therefore to exert a slight snubblng effect and to make the adjustment more accurate.

A suitable cover I such as that shown in Figures 1 and 5 may be provided beneath the sill. The switch may be led out through a cable "I to the sill 66 and the cable it may be led out in any suitable manner to the guide pulleys 340 or 182. Both the wiring 2H and the cable ll may be concealed in suitable portions or arrangements of the spandrel.

It will, of course, be obvious that while the form just described is the preferred form, many other arrangements may be used. Thus, for instance, the lever arm assembly 3 I I with the associated switches, springs and idler pulleys I may be mounted just beneath the window sill. Or the cable ll may be led over a suitable guide pulley to the mechanism which, if desired, may be located in any other suitable, concealed position as, for example, in the cellar below where it may be operated by a motor 3 in the manner herein described.

Likewise the whole switching mechanism may itself be located in some concealed position. Also as shown specifically in Figure 5, an outlet "2 may be provided, the terminals of which are connected into the wires of the circuit between the lever 3H and the motor 3 so that a suitable switch 3" upon an extension cable may be plugged into said outlet, the switch being left in any suitable position for use away from the window where that is desired or convenient.

Various electrical outlets may likewise be provided if desired. on the cover I to facilitate the plugging in of lamps or other electrical devices near the window.

In Figure 3 we have shown a modified arrangement which, however, is not necessarily the preferred form but it may nevertheless be used in exactly the same manner. In this case, the only essential difference is that the motor and drum are themselves mounted upon the lever arm Ill. Otherwise, ,the lever arm and the operation of the switches III and III is the same as that previously described in connection with Figure 4. The operation of the springs Illa and III); is the same as that previously described in connection with Figure 4. The operation of the motor Nlandthewormgearconnection I and the drum III is the same as that previously described in connection with Figure 4; the lever arm III is pivotedupon the pin "2 for the purposes and in the manner hereinbefore described. The only essential difference is the elimination of the idler I and the movement of the drum 183 so thatit with its motor is likewise mounted upon the lever arm 3| l by suitable brackets.

In this case, the pull on the lever arm 3 is not occasioned by the drawing of the cable 8| over an idler pulley which by reason of.the change in direction induced thereby produces a resultant of forces tending to raise the lever, but by the cable itself being strung directly to the drum which produces a direct and immediate force upon the lever by means of its direct tension upon the drum. 1

The raising of the window sash attached to the cable 8| will therefore cause the lever arm 3!! to rise when the sash reaches its uppermost limit or when the sash is otherwise prevented from rising and therefore when tension on the cable increases in the manner hereinbefore described and the unwinding of the drum to its lowermost limit so that the tension upon the cable Si is reduced will permit a dropping of the lever arm 3H to shut off the motor rotation in that direction in a manner hereinbefore described. Obviously, therefore, should the sash stick in its movement in either direction, the circuit will not be overloaded thus blowing fuses, but the switch will operate to shut off the motor.

While this apparatus. furnishes an advantage in that all of the parts thereof are mounted on a single member, the corresponding disadvantage is that a slight shift of the axis of the drum with respect to the cable which is to be wound up thereon by reason of the movement of the lever arm 3 between the limits imposed by springs 3l4a and 31411 tends to cause a grinding of the turns of the cable 8| upon each other, thus tending to create a slight amount 'of additional wear which in ordinary use is hardly material and a. slight amount of noise in the operation of the drum by reason of this grinding effect which likewise is hardly material.

The principle, however, is the same as that set forth in connection with the previously described forms of this operator, it being solely a matter of selection which modification is desired for a particular use.

In Figure 1, we have shown the manner in which the cover 360 of the device of Figures 4 and 5 may be placed in window units so that the device may be used to operate the same. They may, as seen at 400 be attached to the spandrel 4M with a suitable housing 402 being provided for the cable. Or as seen at 403, they may be partially or wholly embedded in the spandrel.

The switch 350 may, as seen, be mounted in the sill or at different points on the device.

Obviously, the switch may be mounted at the side of each window or at any other point in the room, or it may be connected by an extension any signal which may be desired.

cord to the socket 362 and placed anywhere in the room at the convenience of the user. And, if desired, a plurality of switches controlling the same circuit may be mounted at different parts of the room.

vAlso, the mechanism may clearly be mounted at varying points. Thus, it may be in the cellar below and the cable led thereto in any manner as through the spandrel 41; while the switch may be located in the room for ready accessibility.

As will be clearly seen from the cross-sectional view 01 Figure 11, the cable 8| may in the embodiment shown, be attached to the bottom rail or the sash 18 and led over idler 0 to the idler 340 whence it passes over the pulley 34! on the lever 3H for purposes already herein described. 15

A single switch may also be utilized, if desired,

to control a plurality of units.

And, where desired, a single mechanism may be utilized to control several units, suitable clutch arrangements being provided to connect the wind-up drum of any particular unit to the motor and lever. Or each unit may have its own windup drum and lever and a suitable clutch may be provided to connect the motor to the particular one to be operated. These latter expedients, in view of the economy and inexpensiveness of a complete mechanism may, however, not be necessary in practice.

While this disclosure has been described, where examples were required, in connection with the operation of a window sash, it is obvious that it may be used in connection with any closure memher or other member which is to be raised, lowered, swung, moved or slid. It can obviously be applied to a window or door, an end of which is to be lifted or rotated outwardly or inwardly or to various types of closure members.

Gbviously in its basic form this invention is directed to the switching of electrical mechanism in accordance with variations in tension upon a cable. In this connection, therefore, and in this expression of the invention in its purest form, this idea may be applied to almost any embodiment where the limitation of'the tension upon a cable, thread, tape or sheet becomes important.

It may be noted that the tension limiting device may in appropriate cases be connected to and operated by the apparatus which it controls through any suitable system of links, levers and other mechanical connecting means.

In any embodiment, where tension is placed upon a cable by means of a motor and the tension of the cable is not to exceed a certain upward limit, then the use of a switching oil device m prevent the exceeding of such an upward Likewise, the use of such a. device will, if desired, provide an indicator as to the reaching 0! said upward limit.

Also, where a cable is used in any embodiment where the tension is not to fall below a lower limit, then this device can, if desired, be so connected as to switch on or on any motor which is operating or is to be operated when the tension reaches such lower limit or to switch oflf or on Such tension limiting device may be used to control electrically any other form of power supply including hydraulic or steam plants by controlling the valves or other controls therefor by solenoids, relays or other electrical devices in circuit with the switching device of the present invention, the said switching device being responsive to variations in pressure or tension of selected portions of the machine.

Thus in Figure '7, we have illustrated a device which is an adaptation of the present limiting switch of our window operator but which nevertheless functions in exactly the same manner. The cable 500, the tension of which is to be controlled, is led beneath the pulley 51H over the pulley 502 and again beneath the pulley 503. The pulleys 5M and 503 are mounted on the base or casting 504 of the deviceby means oi the pin "5 and 506. The pulley 502 is by means of the pin 501 mounted in the bifurcated end 50! of the reciprocating bolt 509. The bolt 50! extends,

between the top Iii of the casting Ill and the spring seat or cap"! mounted on the bolt. lhe position orthe cap II! is adjustable by means of the nuts Ill and III in order to obtain a predetermined compression of the spring lll.. As will be noted, then the spring Ill tends to drive the bolt ill upwardly. The upper end of the bolt carries an insulated washer I" held in place, for instance, by the screw Ill but which also may, if desired, be adjustable in its position. When the cable III is led beneath the pulleys Ill and Ill but threaded over the pulley III, any

tension thereon tends to pull the belt I" down against the compression of the spring Ill. Any relaxation of such tension permits the spring H topullthebolt-upwardlyoncemore. When.-

for instance, a continuing tension having specific limits (say 5 to Bpounds) is to be applied upon the cable then the spring is so adjusted that when the cable passes beneath the pulleys Ill and "3 and over the pulley III and while the cable remains at such tension, the washer Iii mountedon the bolt 5 will be maintained in a neutral position between the spring elements ill and ill which are insulated from each other and form the frame of the device. Should the tension upon the cable Ill be increased beyond the upper selected limit, then the tendency of the cable to straighten out will tend to pull the bolt downwardly into the position shown by the dotted lines wherein the washer II will depress the spring element I". Should tension be relaxed beyond the lowermost selected limit, then the spring ill will tend to drive the bolt upwardly so as to raise the spring element Ill. The spring elements Ill and ill may then be connected in circuit with different devices including relays, switches, signals and alarms for operating or stop ing the operation of motors of various kinds for the application of brakes or for the operation of signals or warnings.

Thus, for instance, in weaving it is frequently desirable that a predetermined tension be maintained upon the various threads. When the tension is increased beyond a definite limit as by the snag i g of a particular thread, then the thread may be broken and the cloth when finished may be impaired. Likewise, should tension be decreased upona particular thread, then that thread may be loose in the finished cloth and the cloth likewise be impaired. Accordingly, it becomes important to stop the weaving machine immediately upon a change in the tension of any particular thread beyond the limits fixed. I For this purpose a plurality of devices of the type showninFiguresVandBmaybeutilinedone for each thread, so as to insure the continuing predetermined tension on the thread within fixed limits. Where the weaving machine'is electrically driven, the-circuit therein may be made through the spring elements Ill and Ii! and the contacts Ill and Illa to the members it] and Ella. Thereafter. when tension upon any single one of the threads "I is changed, either by the breaking thereof, the tightening thereof, or the thereof, the strikingof the washer Ill against either the element ill or II! will serve to break the circuit to the motor and cause the stopping thereof. or where desired, the change in position of any of the spring elements Sit-and ll! may serve to operate a relay which will open the circuit to the weaving ma-' chine. Or the movement ofeither of the elements ill and SI! may serve to operate a relay asaaaao of the compression spring lil which is captured which will brake the machine or operate valves or cut-oils of the machine in the event that a the machine is not electrically operated.

While the device of Figures 7 and 8 has been 5 described in connection with weaving, obviously it may be used in any connection where a tension limiting device on a cable, cord, thread, tape or chain may be desirable. It may be used in the weaving of wire mesh; in the knitting of various articles; in wire drawing where the wire is pulled at a predetermined tension through dies of fixed diameter. It may be used in paper manufacture. It may be used in printing where in this .case the printed sheet is led under and over drums corresponding to the pulleys Sill, 582, and I". It may be used to control or give a warning of any change in tension of any member of any device.

The device herein described may, if desired,

increase or decrease of tension on a cable connected to a door or window or other opening will serve to operate an alarm. Likewise, an indicating pointer may be applied to any portion of the bolt and a suitable stationary scale provided to show the position of the bolt with respect to the members Sit and 5|! and to provide an indication as to the proximity of the tension on the particular cable, cord, tape, or sheet to the maximum or minimum limit The device of Figures 7 and 8,115 will be seen, may be mounted to operate in any position. The

casting thereof may thus have legs 530 by which it may be attached or mounted upon any object and in any plane.

This type of tension limiting device may take other forms as illustrated in Figures 9 and 10 in which a lever it! is pivoted at "I and carries at one end thereof a pulley SI! which is freely mounted on a pin "3 extending through the bifurcated end 884 of the lever i".

The opposite end of the lever may be limited in its rotation by the adjustable compression springs SIS and "6 which may be adiustably mounted in the casting ll by the adjustable screw "8 and I, the compression springs "5 and I" limiting the movement of the' lever in either direction. A suitable perforation til may be made in the lever III to permit the head of poms and part of the lever maybe deformed as at III in order to provide a suitable abutment for the sprinss. The opposite end of the lever may also carry a projecting bolt "2 which will -operate against the spring members ill and III which in abutment through the contacts 2| andllia with the members III and "la in exactly the manner hereinbefore described in connection with Figures 7 and 8. Each of these members is insulatingly mounted on the insulating block I. Thus when tension of the cable Hi upon the pulley "I is at a predetermined limit then the lever is in balance, about its pivot "I and the member I! is-in balance or neutral between the spring members ill and It.

I Should tension be increased upon the cable "I then the pulley I is dragged so that that end of be used to provide an alarm system wherein any I the screw "0 to be exposed for adjustment purand the member "I may strike against the spring member Gill, thus again breaking the contact. As will be seen, suitable legs or supports 622 may be provided for the casting in order to permit its mounting in any position or in any plane, although only the base plate "A is actually necessary since it may support the lever and the springs and the switches and may be provided with suitable perforations for screws I00 (Figure 6) or other attaching means. The springs E and 606 may each be individually adjustable in order toprovide for maximum and minimum limits. Thus it will be seen that this device, although its original utility is in connection with limiting the operation of any electrical window operator, may nevertheless be applied to any use wherein tension limits on cables, chains,

tapes, cords, wires, threads, or sheets are tobe maintained.

As seen in Figure 6, this arrangement is also readily mountable for operation of a window unit in the manner heretofore described. The plate "IA need merely be screwed to the spandrel and a suitable shield placed thereover or it may be mounted within the spandrel. The motor and drum may be beneath the device, in the cellar below or in or on the iamb alongside, the cable "I being led thereto in any suitable manner.

The present tension limiting device when used in controlling window sash operation may be mounted in various locations. As seen in Figure 12, the device l0 may be mounted above the head stop H of the sash. the cable 8| passing thereover to the drum and motor controlled by the device. may, if desired, be used on only one of a plurality of cables supporting a structure; and, by its adiustment to the tensions on the particular cable, control one or several motors operating the cables. The cables ll of Figure 12 may preferably be operated by a single motor and wound on one or two drums controlled thereby; al-

though they may be operated by separate motors controlled by the device l0.

It will also be noted that devices and controls of the present type are readily applicable to all a cable assists in control-to all types of doors and especially overhead doors-to all types 01 closures-and to all other operations ,wherein variations in tension of a cable can be used to assist in controlling the operation. It will also be obvious that in connection wit a window operator which is to be electrically driven and which is so arranged that the operation thereof is automatically stopped when the window sash is open or closed or stuck in any As also seen in Figure 12, the device the window. Likewise, capsules which become.

conductive upon the presence of moisture may be placed in the circuit to the motor in order to cause the same to operate to close the window sash should a rainfall commence. Likewise, also, Y

photocells maybe connected in the circuit or to operate relays to open or'close the window sash upon changes in light conditions. In addition,

15 also, capacity screens may be connected in circuitor to operate relays to eifect the operation of the motor for purposes of burglar-proofing any room in which units operated by our operator are mounted.

20. The utility of this device will now be obvious and the use thereof in connection with various instrumentalities will be clear, and the many variations thereof in construction and use will nowbe obvious to those skilled in the art We 5 prefer, therefore, to be limited not by the specific disclosures herein, but only by the appended claim.

We claim:

A member biased for'movement in a predetermined direction'and an operator therefor; a

cable connecting said operator and said member; said operator comprising an electric motor and a wind-up drum; said cable being wound on said drum; switching means in circuit with said motor 5 for-actuating said motor selectively to wind-up or unwind said drum; said cable coacting with and normally balancing a lever biased for movement in a direction opposite to that in which the pull ot the cable is exerted; variations in the 40 tension on the cable resulting in a corresponding movement of the lever; and two switching means normally in closed circuit arrangement with said motor and disposed on either side of and in the plane ofmovement of said lever; movement of said lever beyond a'predetermined degree opentypes of windows where variations in tension on ing one of said switches; one of said switches being in circuitwith said motor only when said motor winds up said cable and being arranged 'tobe opened only when the tension of said cable 5 exceeds a predetermined constant; the other of EDMUND H. LUNKE'N GEDRGE A. JUST. 

